Why is Syria OUR responsibility again?

It really boggles the mind why almost every humanitarian disaster is the responsibility of the US to stop.  Yes we have a large military and therefore have the capacity to do something about Syria but it seems that there are other countries in the area that have a greater interest in what is going on in Syria as well as the military wherewithal. Why should we borrow money from China to send our people into harms way in a country where we have few, if any, interests?

Look at Turkey.  They are right next door to Syria and therefore should be the most concerned with the use of chemical weapons.  They also have an Army with 391,000 soldiers and over 3,000 main battle tanks.  Their Air Force has over 200 F-16's.  Why can't they handle Syria's decrepit military that is mired in a Civil War?

Then there is France, which used to occupy Syria and has expressed interest in intervening. Their military is smaller than Turkey's (122,000 soldiers, 270 main battle tanks and 250 modern fighters) but they could definitely do more than the "unbelievably small" attack we apparently are planning.

And finally there are the Saudi's who are actively funding the rebels.  They have 288 very modern aircraft in their Air Force (half of which are F-15's) and so could really help out countries like Turkey or France if they decided to intervene.

So why America?  Why do we have to expend our treasure all the time?  People like to point out how much more we spend than everyone else on the military.  Part of the reason is that so many countries, especially those in Europe, have become so accustomed to our protection that they have invested only nominal amounts to their own defense.  I was shocked when I noticed that Turkey has a 10 to 1 advantage over France in terms of tanks.

In 2012, the US spent about 4.7% of GDP on the military.  Turkey and France spent less than half that, about 2.3%.  The UK is at 2.5%, Italy is at 1.7% and Germany is at a paltry 1.4%.  It seems that we could save billions upon billions of dollars if we just made our allies bear the burden of dealing with these local flare ups that they seem to care so much about.  It's time for us to stop subsidizing their defense.